1. Field of the Invention
The present invention relates to a liquid ejection head that ejects liquid such as ink on a recording material to perform recording, and a method of manufacturing the liquid ejection head.
2. Description of the Related Art
In an ink jet printer that ejects liquid such as ink, ink is supplied from an ink tank to a liquid ejection head including a silicon substrate having energy generating elements provided on a surface thereof, and ink ejection operation is performed to record an image.
An ink ejection structural portion of the liquid ejection head is formed with use of a semiconductor manufacturing technology in order to reduce the size and increase the density.
In the following, with reference to the drawings, the structure of a conventional liquid ejection head is described.
FIG. 4A is a plan view of an ejection orifice forming surface of the conventional liquid ejection head.
FIGS. 4B to 4D are sectional views taken along the line C-C of FIG. 4A in the conventional liquid ejection head. FIGS. 4B to 4D illustrate the internal structure.
On a silicon substrate 104, multiple energy generating elements 711 for generating energy to eject ink are provided. The energy generating elements 711 are arranged at positions corresponding to ejection orifices, respectively.
When viewed from a bubble generating chamber side, on an ink supply path side, round-shaped nozzle filters 101 for capturing foreign matters such as dust mixed inside the ink are provided. The round-shaped nozzle filters 101 are each formed of a photosensitive resin film 102. The round-shaped nozzle filter 101 prevents occurrence of non-ejection of ink caused by clogging of dust inside the nozzle.
The liquid ejection head having such a configuration is disclosed in, for example, Japanese Patent Application Laid-Open No. 2005-161763. The above-mentioned configuration of the liquid ejection head has generally been put into practical use.
As illustrated in FIGS. 4B to 4D, hitherto, there has been adopted a configuration in which a resin film 105 is formed so as to be prevented from protruding from an upper opening edge of a supply port 106 in the silicon substrate 104 to the inner side of the supply port 106. The reason is as follows. In the region in which the resin film 105 is formed, the thickness of the photosensitive resin film 102 is reduced by the thickness of the resin film 105 (about 2 μm). In order to avoid reduction in degree of freedom of nozzle formation, a region that has no need to form the resin film 105 is reduced as much as possible.
However, in the above-mentioned configuration, in the vicinity of the nozzle filter 101, the photosensitive resin film 102 and a silicon nitride film 103 are directly bonded to each other. Therefore, vibrations to be applied during the manufacturing steps (for example, ultrasonic vibrations used when a flow path pattern member (mold) for forming a bubble generating chamber and a flow path pattern forming a flow path is removed) are directly transmitted to the silicon nitride film 103. Therefore, when the supply port 106 is formed by etching, there is a fear that an end portion (remainder portion) 107 of the silicon nitride film 103, which is generated in an exposed manner at the upper opening edge, is damaged to be chipped. The remainder portion 107 damaged as described above may remain inside the ink flow path, and hence there is a fear that nozzle clogging occurs in the ejection orifice.
When the nozzle is clogged, ejection failure and non-ejection may occur, resulting in a risk of deterioration in recording image quality.